The subject matter herein relates generally to solar junction boxes for solar panels.
Photovoltaic (PV) modules or arrays, such as solar panels, produce electricity from solar energy. Electrical power produced by PV modules reduces the amount of energy required from non-renewable resources such as fossil fuels and nuclear energy. Significant environmental benefits are also realized from solar energy production, for example, reduction in air pollution from burning fossil fuels, reduction in water and land use from power generation plants, and reduction in the storage of waste byproducts. Solar energy produces no noise, and has few moving components. Because of their reliability, PV modules also reduce the cost of residential and commercial power to consumers.
PV cells are essentially large-area semiconductor diodes. Due to the photovoltaic effect, the energy of photons is converted into electrical power within a PV cell when the PV cell is irradiated by a light source such as sunlight. PV cells are typically interconnected into solar modules that have power ranges of up to 100 watts or greater. For large PV systems, special PV modules are produced with typical power range of up to several 100 W. A photovoltaic module is the basic element of a photovoltaic power generation system. A PV module has many solar cells interconnected in series or parallel, according to the desired voltage and current parameters. PV cells are connected in series with thin contacts, such as a foil. The foil is terminated to a solar junction box, which may electrically connect groups of the PV cells and/or solar panels.
The solar junction box is typically connected to the back side of the solar panel, such as to a back sheet. The foil is terminated to a corresponding terminal in the junction box. In typical PV modules, many solar panels are connected in series using electrical cables routed between corresponding junction boxes of such solar panels. Additionally, some of the junction boxes are electrically connected to other equipment, such as batteries or power converters, and take the collected solar energy to such other equipment. The electrical cables are typically terminated to the terminals in the junction boxes with a permanent connection. For example, the electrical cables may be soldered to the terminals. Such connections are typically made in the manufacturing factory rather than in the field. Other systems use connectors provided at ends of the cables to interconnect the junction boxes.
As PV systems become more advanced, it is becoming desirable to provide additional functionality within the PV system. For instance, there is a need to integrate electronics into the PV system. For example, it is desirable to introduce diodes to control the flow of electricity in the solar panels. Some junction boxes contain integrated circuit boards, which are directly attached to the junction box and are soldered to the terminals and/or wires. Such circuit boards are not removable and replaceable in the field.
A need remains for field installable circuit boards to solar junction boxes.